Add vmin arg option to Circos.radar_chart()

src/pycirclize/circos.py

@@ -180,6 +180,7 @@ def radar_chart(
         table: str | Path | pd.DataFrame | RadarTable,
         *,
         r_lim: tuple[float, float] = (0, 100),
+        vmin: float = 0,
         vmax: float = 100,
         fill: bool = True,
         marker_size: int = 0,
@@ -203,6 +204,8 @@ def radar_chart(
             Table file or Table dataframe or RadarTable instance
         r_lim : tuple[float, float], optional
             Radar chart radius limit region (0 - 100)
+        vmin : float, optional
+            Min value
         vmax : float, optional
             Max value
         fill : bool, optional
@@ -244,6 +247,10 @@ def radar_chart(
         circos : Circos
             Circos instance initialized for radar chart
         """
+        if not vmin < vmax:
+            raise ValueError(f"vmax must be larger than vmin ({vmin=}, {vmax=})")
+        size = vmax - vmin
+
         # Setup default properties
         grid_line_kws = {} if grid_line_kws is None else deepcopy(grid_line_kws)
         for k, v in dict(color="grey", ls="dashed", lw=0.5).items():
@@ -269,11 +276,12 @@ def radar_chart(
             if not 0 < grid_interval_ratio <= 1.0:
                 raise ValueError(f"{grid_interval_ratio=} is invalid.")
             # Plot horizontal grid line & label
-            stop, step = vmax + (vmax / 1000), vmax * grid_interval_ratio
-            for v in np.arange(0, stop, step):
-                track.line(x, [v] * len(x), vmax=vmax, arc=circular, **grid_line_kws)
+            stop, step = vmax + (size / 1000), size * grid_interval_ratio
+            for v in np.arange(vmin, stop, step):
+                y = [v] * len(x)
+                track.line(x, y, vmin=vmin, vmax=vmax, arc=circular, **grid_line_kws)
                 if show_grid_label:
-                    r = track._y_to_r(v, 0, vmax)
+                    r = track._y_to_r(v, vmin, vmax)
                     # Format grid label
                     if grid_label_formatter:
                         text = grid_label_formatter(v)
@@ -283,7 +291,7 @@ def radar_chart(
                     track.text(text, 0, r, **grid_label_kws)
             # Plot vertical grid line
             for p in x[:-1]:
-                track.line([p, p], [0, vmax], vmax=vmax, **grid_line_kws)
+                track.line([p, p], [vmin, vmax], vmin=vmin, vmax=vmax, **grid_line_kws)
 
         # Plot radar charts
         if isinstance(cmap, str):
@@ -296,15 +304,16 @@ def radar_chart(
             line_kws = line_kws_handler(row_name) if line_kws_handler else {}
             line_kws.setdefault("lw", 1.0)
             line_kws.setdefault("label", row_name)
-            track.line(x, y, vmax=vmax, arc=False, color=color, **line_kws)
+            track.line(x, y, vmin=vmin, vmax=vmax, arc=False, color=color, **line_kws)
             if marker_size > 0:
                 marker_kws = marker_kws_handler(row_name) if marker_kws_handler else {}
                 marker_kws.setdefault("marker", "o")
                 marker_kws.setdefault("zorder", 2)
                 marker_kws.update(s=marker_size**2)
-                track.scatter(x, y, vmax=vmax, color=color, **marker_kws)
+                track.scatter(x, y, vmin=vmin, vmax=vmax, color=color, **marker_kws)
             if fill:
-                track.fill_between(x, y, vmax=vmax, arc=False, color=color, alpha=0.5)
+                fill_kws = dict(arc=False, color=color, alpha=0.5)
+                track.fill_between(x, y, y2=vmin, vmin=vmin, vmax=vmax, **fill_kws)  # type:ignore
 
         # Plot column names
         for idx, col_name in enumerate(radar_table.col_names):